Wvw most common and popular roles are:
Tower ranger
The five signet mech
Stone heart ele, tempest most of the times, but Ive seen all kinds of ele playing this abomination
Cele harb, literal god of the battleground
The minstrel main. Doesnt matter class or spec, you cant go wrong with this stat combo
Honorable mention to shadow arts thieves, havent seem much of those lately